Dual clutch transaxle

ABSTRACT

A dual clutch transaxle is provided that includes a dual clutch assembly, an input shaft assembly, a counter shaft assembly, a shift assembly and at least one output assembly. The dual clutch assembly has a dual clutch axis and includes a first clutch shaft and a second clutch shaft. The input shaft assembly includes a nested first inner input shaft and a second outer input shaft that are operationally coupled to the first clutch shaft and a second clutch shaft. An input shaft axis is offset from the dual clutch axis of the dual clutch assembly. A plurality of drive gears of the input shaft assembly are operationally coupled to a plurality of driven gears of the counter shaft assembly. The shift assembly is operationally coupled to select. The at least one output assembly is operationally coupled to the counter shaft assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to U.S. Provisional Application Ser.No. 62/286,198 entitled “Dual Clutch Transmission System”, filed on Jan.22, 2016 and U.S. Provisional Application Ser. No. 62/286,492 entitled“Dual Clutch Transmission System,” filed on Jan. 25, 2016 which are bothincorporated in their entirety herein by reference.

BACKGROUND

A dual clutch transmission is a transmission for a motorized vehiclethat has multiple gears where the odd gears (1,3,5 . . . ) arecontrolled by one clutch and the even gears (2,4,6 . . . ) arecontrolled by a second independent clutch. Dual clutches can be housedeither in one housing or in separate housings. In operation, assuming afirst clutch controls the odd gears and a second clutch controls theeven gears) when the vehicle is being driven in first gear, the firstclutch is engaged and second clutch is open. When a shift to second gearis determined to be necessary either by a controller or a driver, amechanism moves a dog clutch or synchronizer to engage the second gear.With the second clutch still open, no power is transmitted through thesecond gear. To make the shift from first gear to second gear, the firstclutch will open and the second clutch will close. Power is now beingtransmitted through the second gear. Because the first clutch is open,no power is going through the first gear. When a shift to third gear isdetermined to be necessary, the process repeats itself and a mechanismmoves the odd dog clutch or synchronizer to the third gear and thesecond clutch will open and first clutch will close. This process ofmoving a mechanism to engage a dog clutch or synchronizer then openingone clutch and closing the other repeats for all upshifts and alldownshifts. A standard vehicle layout has the transmission in the middleof the vehicle, in front of the motor, with prop shafts running from thedual clutch transmission to a front and rear bevel gear cases is typicaland easily packaged into the vehicle. However, many recreationalvehicles such as, but not limited to, utility task vehicles (UTV) havelimited space between the passenger compartment and the reardifferential where a dual clutch transmission or transaxle would belocated.

For the reasons stated above and for other reasons stated below whichwill become apparent to those skilled in the art upon reading andunderstanding the present specification, there is a need in the art fordual clutch transaxle that effectively and efficiently fits within thesize and location limitations of vehicles.

SUMMARY OF INVENTION

The above-mentioned problems of current systems are addressed byembodiments of the present invention and will be understood by readingand studying the following specification. The following summary is madeby way of example and not by way of limitation. It is merely provided toaid the reader in understanding some of the aspects of the invention.

In one embodiment, a dual clutch transaxle is provided that includes adual clutch assembly, an input shaft assembly, a counter shaft assembly,a shift assembly and at least one output assembly. The dual clutchassembly includes a first inner clutch shaft and a second outer clutchshaft. The dual clutch assembly has a dual clutch axis. The dual clutchassembly is further configured to be coupled to receive torque from amotor. The input shaft assembly includes a nested first inner inputshaft and a second outer input shaft. The input shaft assembly has aplurality of drive gears. The input shaft assembly further has an inputshaft axis. The input shaft axis is offset from the dual clutch axis ofthe dual clutch assembly. The first inner clutch shaft of the dualclutch assembly is operationally coupled to one of the first inner inputshaft and the second outer input shaft of the input shaft assembly andthe second outer clutch shaft of the dual clutch assembly isoperationally coupled to the other of the first inner input shaft andthe second outer input shaft of the input shaft assembly. The countershaft assembly has a plurality of driven gears. The plurality of drivegears of the input shaft assembly are operationally coupled to theplurality of driven gears of the counter shaft assembly. The shiftassembly is operationally coupled to at least one of the input shaftassembly and the counter shaft assembly to select gearing of the dualclutch transaxle. The at least one output assembly is operationallycoupled to the counter shaft assembly. The output assembly is configuredto provide an output of the dual clutch transaxle.

In another embodiment, another dual clutch transaxle is provided. Thedual clutch transaxle includes a dual clutch assembly, an input shaftassembly, a counter shaft assembly, a shift drum assembly, first outputassembly and a second output assembly. The dual clutch assembly includesa first clutch shaft and a second clutch shaft. The dual clutch assemblyhaving a dual clutch axis. The dual clutch assembly is configured toreceive torque from a motor. The input shaft assembly includes a nestedfirst inner input shaft and a second outer input shaft. The first innerinput shaft has at least one drive gear and the second outer input shafthas at least one other drive gear. The input shaft assembly further hasan input shaft axis. The first clutch shaft of the dual clutch assemblyis operationally coupled to one of the first inner input shaft and thesecond input shaft of the input shaft assembly and the second outerclutch shaft of the dual clutch assembly operationally coupled to one ofthe other of the first inner input shaft and the second outer inputshaft of the input shaft assembly. The counter shaft assembly has atleast a driven gear engaged with the at least one drive gear and atleast one other driven gear engaged with the at least one other drivegear of the input shaft assembly. The shift assembly is operationallycoupled to at least one of the input shaft assembly and the countershaft assembly to select gearing of the dual clutch transaxle. The firstoutput assembly is operationally coupled to the counter shaft assembly.The first output assembly is configured to provide a first output of thedual clutch transaxle. The first output assembly having an output axisthat is transverse and below the input shaft axis. The second outputassembly is operationally coupled to the counter shaft assembly.

In still another embodiment, a vehicle provided. The vehicle includes amotor, a dual clutch transaxle, a set of rear wheels, a set of frontwheels and a front differential. The motor provides torque. The dualclutch transaxle includes a dual clutch assembly, an input shaftassembly, a counter shaft assembly, a first output assembly and a secondoutput assembly. The dual clutch assembly is coupled to receive thetorque from the motor. The dual clutch assembly includes a first innerclutch shaft and a second outer clutch shaft. The dual clutch assemblyhas a dual clutch axis. The input shaft assembly includes a nested firstinner input shaft and a second outer input shaft. The input shaftassembly has a plurality of drive gears. The input shaft assemblyfurther has an input shaft axis. The input shaft axis is offset from thedual clutch axis of the dual clutch assembly. The first inner clutchshaft of the dual clutch assembly is operationally coupled to one of thefirst inner input shaft and the second outer input shaft of the inputshaft assembly and the second outer clutch shaft of the dual clutchassembly operationally coupled to the other of the first inner inputshaft and the second outer input shaft of the input shaft assembly. Thecounter shaft assembly has at least a driven gear engaged with the atleast one drive gear and at least one other driven gear engaged with theat least one other drive gear of the input shaft assembly. The shiftdrum assembly is operationally coupled to at least one of the inputshaft assembly and the counter shaft assembly to select gearing of thedual clutch transaxle. The first output assembly is operationallycoupled to the counter shaft assembly. The first output assembly isconfigured to provide a first output of the dual clutch transaxle. Thefirst output assembly has a first output axis that is transverse to thedual clutch axis. The second output assembly is operationally coupled tothe counter shaft assembly. The set of rear wheels are operationallycoupled to the output differential. The front differential isoperationally coupled to the second output and the set of front wheelsis operationally coupled to the front differential.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more easily understood and furtheradvantages and uses thereof will be more readily apparent, whenconsidered in view of the detailed description and the following figuresin which:

FIG. 1 is a first side perspective view of a dual clutch transaxle ofone embodiment of the present invention;

FIG. 2 is a first side view of the dual clutch transaxle of FIG. 1;

FIG. 3 is a second side perspective view of the dual clutch transaxle ofFIG. 1;

FIG. 4 is a second side view of the dual clutch transaxle of FIG. 1;

FIG. 5 is a first end view of the dual clutch transaxle of FIG. 1;

FIGS. 6A through 6D illustrate unassembled components that make up atleast in part the dual clutch transaxle of FIG. 1;

FIG. 7 is a partial cross-sectional first side view of the dual clutchtransaxle of FIG. 1 illustrating how the inner input shaft and outerinput shaft interact with the inner and outer clutch shafts;

FIG. 8 is a partial cross-sectional top view of the dual clutchtransaxle of FIG. 1 illustrating the how the inner input shaft and outerinput shaft interact with the countershaft;

FIG. 9 is a vehicle of an embodiment implementing the dual clutchtransaxle of FIG. 1;

FIG. 10 is a first side perspective view of dual clutch transaxle ofanther embodiment;

FIG. 11A is a second side perspective view of the dual clutch transaxleof FIG. 10;

FIG. 11B is another second side perspective view of the dual clutchtransaxle of FIG. 10;

FIG. 12 is a partial cross-sectional top view of the dual clutchtransaxle of FIG. 10 illustrating how the input shaft interacts with thecountershaft in this embodiment;

FIG. 13 is a first side perspective view of a dual clutch transaxle ofanother embodiment;

FIG. 14 is a second side perspective view of the dual clutch transaxleof FIG. 13; and

FIG. 15 is a partial cross-sectional top view of the dual clutchtransaxle of FIG. 13 illustrating how the input shaft interacts with thecountershaft in this embodiment.

In accordance with common practice, the various described features arenot drawn to scale but are drawn to emphasize specific features relevantto the present invention. Reference characters denote like elementsthroughout Figures and text.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof, and in which is shownby way of illustration specific embodiments in which the inventions maybe practiced. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that changesmay be made without departing from the spirit and scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the present invention isdefined only by the claims and equivalents thereof.

Embodiments of the present invention provide a dual clutch transaxlehaving a dual clutch assembly, an input shaft assembly and a countershaft assembly. In embodiments, an input shaft assembly axis is in adifferent location that dual clutch assembly axis. In some embodiments,an output differential assembly is positioned below at least one of theinput shaft assembly and counter shaft assembly. Moreover, someembodiments require no gear reduction out of the dual clutch assembly. Afirst embodiment of a dual clutch transaxle 100 is illustrated in FIGS.1 through 8. FIGS. 1-5 illustrate different views of the assembled dualclutch transaxle 100 while FIGS. 6A through 6D illustrate theunassembled components that make up assemblies the dual clutch transaxle100. Further FIGS. 7 and 8 illustrate cross-sectional views of somecomponents of the dual clutch transaxle 100. The following descriptionof the dual clutch transaxle 100 is provided in light of FIGS. 1 through8. The dual clutch transaxles in embodiments are shown without casing orhousings for illustration purposes. It is noted that at least some ofthe bearing shown in the Figures would be engaged with a casing orhousing of the dual clutch transaxle.

Referring to FIG. 6A, the dual clutch transaxle 100 includes a dualclutch assembly 120, and input shaft assembly 140 and a counter shaftassembly 220. FIG. 6A illustrates the assemblies unassembled. The dualclutch assembly 120 in this embodiment includes a dual clutch 121. Thedual clutch 121 in this embodiment is a nested dual clutch including afirst clutch 121 a and a second clutch 121 b as best illustrated in FIG.7. Referring back to FIG. 6A, the dual clutch assembly 120 furtherincludes a first clutch shaft 122 and a second clutch shaft 124. In adual clutch nested assembly, the first clutch shaft is a first innerclutch shaft 122 and the second clutch shaft is a second outer clutchshaft 124. The first inner clutch shaft 122 includes a first innerclutch gear 122 a and inner end clutch splines 122 b. The second outerclutch shaft 124 has a central passage 124 a in which a portion of theinner clutch shaft 122 is received. The second outer clutch shaft 124further includes a second outer clutch gear 124 c and outer end clutchsplines 124 b. The dual clutch assembly 120 further includes bearings126, 128, 130 and 132 mounted on the first inner clutch shaft 122 andbearing 134 mounted on the second outer clutch shaft 124. The dualclutch assembly further includes a seal 136. As best illustrated in FIG.7, the inner end clutch splines 122 b of the first inner clutch shaft122 mate with splines of the first clutch 121 a to lock rotation of thefirst inner clutch shaft 122 with the first clutch 121 a of the dualclutch 121. The outer end clutch splines 124 b of the second outerclutch shaft 124 mate with splines of the second clutch 121 b to lockrotation of the second outer clutch shaft 124 with the second clutch 121b of the dual clutch 121. The seal 136, is positioned between a coverplate 123 and a torque clutch input shaft 138 as illustrated in FIG. 7.The torque clutch input shaft 138 provides torque from a crank shaft ofan engine 502 (shown in FIG. 9) to the dual clutch assembly 120.

Referring back to FIG. 6A the input shaft assembly 140 of the dualclutch transaxle 100 unassembled is shown. The input shaft assembly 140in this embodiment includes a first inner input shaft 142 and a secondouter input shaft 144. A nesting of the inner input shaft 142 in theouter input shaft 142 is best illustrated in the cross-sectional viewsof FIGS. 7 and 8. The first inner input shaft assembly 142 includes afirst set of splines 142 a, an inner input shaft first driven gear 143and second set of splines 142 b. The second outer input shaft 144includes a second drive gear 144 a and a reverse drive sprocket 144 b.Mounted on a first end of the first input shaft 142 is bearing 146,retaining ring 148, a first drive gear 150, washer 152, washer 154,bearing 156, retaining ring 158, first shift dog 160, retaining clip162, washer 164, bearing 166, third drive gear 168, bearing 170, washer172 and bearing 174. Mounted on the second outer input shaft 144 isbearing 176, fourth drive gear 178, washer 180, retaining ring 182,shift dog 184, retaining ring 186, retaining ring 188, washer 190,bearing 192, sixth drive gear 194, outer input shaft second driven gear196, bearing 198 and bearing 202. Further mounted on a second end of thefirst input shaft 142 is bearing 204, fifth drive gear 206, washer 208,retaining ring 210, fourth shift dog 212 and bearing 214. FIG. 7 bestshows how the components of the input shaft assembly 140 are assembled.

The dual clutch transaxle 100 further includes a counter shaft assembly220. The counter shaft assembly 220 includes a counter shaft 222. Thecounter shaft 222 includes outer splines 222 a, 222 b, 222 c and 222 d.The counter shaft 222 also includes fourth driven gear 223, sixth drivengear 224 and fifth driven gear 225. Mounted on a first side of thecounter shaft 222 is bearing 226, retaining ring 228, first driven gear230, retaining ring 232, third driven gear 234, second driven gear 236,retaining ring 238, second shift dog 240, bearing 242, retaining ring244, washer 246, bearing 248 and sprocket 250. A chain 252 is engagedwith sprocket 250. On the other side of the counter shaft 222 ismounted, a retaining ring 254, a counter shaft output drive gear 256, apark shift dog 258, a retaining ring 260 and a bearing 262. FIG. 8 bestshows how the components of the counter shaft assembly 220 areassembled. As illustrated in FIG. 8, splines 222 a of the counter shaft222 lock rotation of the first driven gear 230 with the counter shaft222. Splines 222 b of the counter shaft 222 lock rotation of the thirddriven gear 234 with the counter shaft 222. Splines 222 c of the countershaft 222 lock rotation of the second shift dog 240 with rotation of thecounter shaft 222. Finally, splines 222 d of the counter shaft 222 lockrotation of the park shift dog 258 and counter shaft output drive gear256 with rotation of the counter shaft 222.

Further components of the dual clutch transaxle 100 is illustrated inFIG. 6B. The dual clutch transaxle 100 includes an idler assembly 270and a front output assembly 282. The idler assembly 270 includes anidler shaft 272 with an idler gear 272 a. Mounted on the idler shaft 272is a bearing 274, a second stage gear 276, a retaining ring 278 and abearing 280. The second stage gear 276 is rotationally locked to theidler shaft 272 via splines 272 b. The assembled idler assembly 270 isbest shown in FIG. 3. The front output assembly 282 includes a frontoutput shaft 284 that has a front output gear 284 a. Mounted on thefront output shaft 284 is bearing 286, bearing 288 and seal 290. Theassembled front output assembly is also best shown in FIG. 3 ad FIG. 4.The front output assembly 282 (second output assembly) has a frontoutput axis 283 that is parallel to the dual clutch axis 106 in anembodiment. Note the dual clutch transaxle 100 is shown without ahousing for illustration purposes. Bearings 288 and 286 as well as seal290 would engage the housing.

The dual clutch transaxle 100 also includes an electric shift motor 102with a power port 104. A gear cluster made up of a first assembly 314, asecond assembly 304 and a third assembly 292 as illustrated in theunassembled view of FIG. 6B. The first assembly 314 includes a motorshaft 316 that is operationally coupled to the electric motor 102,bearing 318, bearing 320, first cluster gear 322, first pinion gear 324,bearing 326 and bearing 328. The second assembly 304 includes a clustershaft 306 upon which is mounted bearing 308 a second cluster gear 310and bearing 312. The third assembly 292 includes a cluster shaft 294upon which is mounted bearing 296, bearing 298 and cluster gear 302.Cluster gears 322, 310 and 302 and can be seen assembled at in FIGS. 1through 5. The gear cluster transfers the rotational output from theelectric shift motor 102 to the shift drum assembly 450 via shift drumgear 458 discussed further below. Further illustrated in FIG. 6B is apark assembly 330. The park assembly includes a park rail shaft 332 anda park pawl 334. An assembled park pawl is best illustrated in FIG. 3.

Referring to FIG. 6C, unassembled first shift park assembly 336 and asecond shift park assembly 360 is illustrated. The first shaft parkassembly 336 includes a first shift shaft 346. Mounted on a first sideof the first shift shaft 346 is a first sector gear 344, O-ring 342,bell crank 340 and nut 338. Mounted on a second side of the first shiftshaft 346 is a second sector gear 348, a first portion of a park cam 350a, a torsion spring 352, a second portion of the park cam 354 and aretaining ring 356. The second shift park assembly 360 includes a secondshift shaft 362. Mounted on the second shift shaft 362 is a detent star364, a third sector gear 366, a fourth sector gear 368, and O-ring 370,a thrust washer 372 and a snap ring 374. The first shift shaft assembly336 and the second shift park assembly 360 assembled can be seen atleast in FIGS. 3 through 5.

In embodiments, a linkage of some type such as a cable, linkage rod,etc. connects into bell crank 340. When the linkage is pulled, the bellcrank 340 rotates first shift shaft 346 which is attached via spline tofirst sector gear 344. This sector gear 344 is attached to third sectorgear 366 which is splined to second shift shaft 362 which in turn issplined to fourth sector gear 368. The fourth sector gear 368 mesheswith second sector gear 348 back on first shift shaft 346. Second sectorgear 348 is not rotationally constrained to first shift shaft 346 so itcan rotate relative to it. Second sector gear 348 is attached to firstportion park cam 350 a so when second sector gear 348 rotates, firstportion park cam 350 a rotates with it. Park cam 350 a is connected tosecond portion park cam 354 through a torsion spring 352. The torsionspring 352 is used so that when the park cams 350 a rotates, if parkpawl 334 hits the top of a dog clutch on park shift dog 258, the torsionspring 352 will load up. Due to this loading, when the park shift dog258 rotates to a point where the park pawl 334 can fall into a notch,the torsion spring completes rotation of second portion park cam 354which cams the park pawl 334 about park rail shaft 332 to engage dogteeth in park shift dog 258 completing the shift to park without anyadditional input from the driver. The park shift rail 332 is locked intoa gear case (not shown) so when the park pawl 334 locks into the parkshift dog 258, the counter shaft 222 is locked to the gear case and dualclutch transaxle 120 is in park. This sub-assembly also includes detentstar 364 which works with a detent pawl (not shown) that is a springloaded detent mechanism that can be a plunger style, pawl style or anyother mechanism to make a detent shift force noticeable to the driver.This detent star and loading mechanism is designed such that when thedetent plunger or pawl rotates over a finger of the detent star 364 itwill rotate the first portion park cam 350 a and load the torsion spring352 and hold the torsion spring 352 in a loaded state. As mentionedpreviously, if the park pawl 334 can hit the opening in park shift dog258 the park pawl will drop in and you have park. If the park pawl 334does not hit the opening in the dog clutch in park shift dog 258, thetorsion spring will load up so when the park shift dog rotates and thepark pawl can hit the opening in the dog clutch in park shift dog 258,it will drop in and engage park.

FIG. 6D further shows other unassembled components of the dual clutchtransaxle 100. FIG. 6D illustrates an output differential assembly 380,a gear assembly 416, a shift drum assembly 450 and a shift fork assembly460. The output differential assembly 380 includes a bearing 382, anengagement dog 384, a differential carrier 386, a washer 402, a firstoutput gear 404. The output differential assembly 380 further includes afirst bevel pinion 406 a, a second bevel pinion 406 b, a differentialpin 390 to hold the first bevel pinion 406 a and second bevel pinion 406b to differential carrier 386, a second output gear 408, a washer 410, adowel pin 401, a ring gear 412 and a bearing 414. The outputdifferential assembly assembled is best illustrated in FIG. 5. Theunassembled gear assembly 416 of FIG. 6D includes a bevel pinion 418with a bevel pinon gear 418 a. Mounted on a shaft of the bevel pinion isa bearing 420, a bearing cover 422, a third stage gear 424, a pinionbearing nut 426, a spacer 428, a forward gear 430 and bearing 432. Anassembled gear assembly 416 is best illustrated in FIG. 2.

An unassembled shift drum assembly 450 is also illustrated in FIG. 6D.The shift drum assembly 450 includes a shift drum 452. The shift drum452 includes a plurality of cam tracks. In the example embodiment shownthe plurality of cam tracks includes a first cam track 452 a, a secondcam track 452 b, a third cam track 452 c and a fourth cam track 452 d.Mounted on a first end of the shift drum 452 is a bearing 454. Mountedon a second end of the shift drum 452 is a bearing 456 and a shift drumgear 458. The shift fork assembly 460 includes a shift rail 462 uponwhich a first shift fork 464, a second shift fork 466, a third shiftfork 468 and fourth shift fork 470 is mounted. Each shift fork 464, 466,468 and 470 includes a follower tab that is received in an associatedcam track of the shift drum 452 when assembled. In particular, the firstshift fork 464 includes a first follower tab 464 a which is received infirst cam track 452 a of the shift drum 452. The second shift fork 466includes a second follower tab 466 b that is received in the second camtrack 452 b of the shift drum 452. The third shift fork 468 includes athird follower tab 468 c that is received in the third cam track 452 cof the shift drum 452. Moreover, the fourth shift fork 470 includes afourth follower tab 470 d that is received in the fourth cam track 452 dof the shift drum 452. The assembled shift drum assembly 450 and theshift fork assembly 460 is best illustrated in FIG. 2.

Torque produced by and engine 502 (illustrated in FIG. 9) is provided tothe dual clutch dual clutch assembly 120 which in turn provides thetorque to the input shaft assembly 140 as best illustrated in FIG. 7. Inparticular, the first inner clutch gear 122 a of the first inner clutchshaft 122 is engaged with the input shaft second driven gear 196 of theinput shaft assembly 140. The first inner clutch shaft 122 is engagedwith the first clutch 121 a of the dual clutch 121. The input shaftsecond driven gear 196 of the input shaft assembly 140 is engaged withthe first inner clutch gear 122 a of the dual clutch 121. Hence, torquethrough the first clutch 121 a is provided to the second outer inputshaft 144 of the input shaft assembly 140. The second outer clutch gear124 c of second outer clutch shaft 124 of the dual clutch assembly 120is engaged with the inner input shaft first driven gear 143 of the firstinner input shaft 142 of the input shaft assembly 140. Hence, torquethrough the second clutch 121 b is provided to the first inner inputshaft 142 of the input shaft assembly 140. The dual clutch 121 may beactivated electrically or via hydraulic system.

Referring to FIG. 2, during operation, when the electric motor isactivated to make a shift, the shift drum 452 rotates via shift drumgear 458 engaging the cluster gears 322, 310 and 302 which are in turnoperationally coupled to the first pinon gear 324 and the motor shaft316 of the electric motor 102. As the shift drum 452 rotates, thefollower tabs 464 a, 466 b, 468 c and 470 d received in the respectivecam tracks 452 a, 452 b, 452 c and 452 d cause the respective shiftforks 464, 466, 468 and 470 to move. The cam profile of each respectivecam track 452 a, 452 b, 452 c and 452 d are designed to accomplish adesired shift change of the dual clutch transaxle 100 as the shift drum452 rotates.

In the example embodiment of the dual clutch transaxle 100, the firstshift fork 464 is engaged with the first shift dog 160 of the inputshaft assembly 140. The first shift dog 160 selectively locks either thefirst drive gear 150 or the third drive gear 168 with rotation of thefirst inner input shaft 142 depending on the location of the first shiftfork 464 which is controlled by the shift drum 452 as discussed above.The second shift fork 466 is engaged with the second shift dog 240 onthe counter shaft 222 of the counter shaft assembly 220. The secondshift dog 240 selectively locks rotation of counter shaft 222 with therotation of either the second driven gear 236 or the sprocket 250. Thethird shift fork 468 is engaged with the third shift dog 184 of theinput shaft assembly 140. The third shift dog 184 selectively lockseither the fourth drive gear 178 or the sixth drive gear 194 with therotation of the second outer input shaft 144 depending on the locationof the third shift fork 468 which is controlled by the shift drum 452 asdiscussed above. Finally, the fourth shift fork 470 is engaged with thefourth shift dog 212. The fourth shift dog 212 selectively locks thefifth drive gear 206 to the rotation of the first inner input shaft 142.

As best illustrated in FIG. 8, the interaction between the input shaftassembly 140 and the counter shaft assembly 220 is described. Asillustrated, the first drive gear 150 of the input shaft assembly 140 isengaged with the first driven gear 230 of the counter shaft assembly220. The third drive gear 168 of the input shaft assembly 140 is engagedwith the third driven gear 234 of the counter shaft assembly 220. Thesecond drive gear 144 a of the input shaft assembly 140 is engaged withthe second driven gear 236 of the counter shaft assembly 220. Thereverse drive sprocket 144 b of the input shaft assembly 140 is engagedwith the chain 252 which is in turn engaged with sprocket 250 of thecounter shaft assembly 220. The fourth drive gear 178 is engaged withthe fourth driven gear 223 of the counter shaft assembly 220. The sixthdrive gear 194 of the input shaft assembly 140 is engaged with the sixthdriven gear 224 of counter shaft assembly 220. Finally, the fifth drivegear 206 of the input shaft assembly 140 is engaged with the fifthdriven gear 225 of the counter shaft assembly 220.

Further operational connections are described below. As best illustratedin FIG. 3, the counter shaft output drive gear 256 of the counter shaftassembly 220 is engaged with the second stage gear 276 of the idlerassembly 270. The idler gear 272 a of the idler assembly 270 is engagedwith the third stage gear 424 of the gear assembly 416. The forward gear430 of the gear assembly in turn is engaged with the front output gear284 a of the front output assembly 282. The bevel pinion gear 418 a ofthe bevel pinion 418 of the gear assembly 416 engaging the ring gear 412of the output differential assembly 380. Although the output assembly380 is described as an output differential assembly, other types of theoutput assemblies could be used such as a lock spool assembly.

Referring to FIGS. 7 and 8 a description of changing gears from secondgear to third gear is provided to better help in the understanding ofembodiments. Torque from an engine comes into the dual clutch 121 from atorsional damper through a connection of the torque clutch input shaft138 as illustrated in FIG. 7. First clutch 121 a will be closed andlocked at this point. The second clutch 121 b will be open. Shift dog240, illustrated in FIG. 8, will be engaged with the second driven gear236. The power path at this point is through the torque clutch inputshaft 138, first clutch 121 a, inner end clutch splines 122 b, firstinner clutch shaft 122, input shaft second driven gear 196, second drivegear 144 a, second driven gear 236, second shift dog 240, counter shaft222 and then through the rest of the dual clutch transaxle 100 to theoutput differential assembly 380 and the front output assembly (secondoutput assembly) 282. When it is time to shift into third gear,initially everything stays as listed above except the shift drum 452 ofthe shift drum assembly 450 rotates to a third gear per selection. Thefirst shift dog 160 moves in response to the rotation of the shift drum452 to engage the third gear 168. This is preselection since all thepower is still going through the second gear set as discussed above.Hence at this point no torque is transmitted to the third drive gear 168because the second clutch 121 b is still open at this point. In a fewmilliseconds, the first clutch 121 a opens as the second clutch 121 bcloses. This allows for a very rapid shift from second gear to thirdgear. The power path is now through the torque clutch input shaft 138,second clutch 121 b, outer end clutch splines 124 b, second outer clutchshaft 124, inner input shaft first driven gear 143, first inner inputshaft 142, first shift dog 160, third drive gear 168, third driven gear234, counter shaft 222 and then through the rest of the dual clutchtransaxle 100 to the output differential assembly 380 and the frontoutput assembly (second output assembly) 282. The use of the dual clutchdual input shaft arrangement ensures that torque is always maintained tothe ground during the handoff from the first clutch 121 a to the secondclutch 121 b. The opening and closing of the first and second clutches121 a and 121 b may be controlled via a control system that implementsan electronic, hydraulic or combination system. For example, in anembodiment, an electronic controller may be used that monitors inputssuch as, but not limited to, engine speed, throttle position and vehiclespeed and decides when to shift based on those inputs. When it is timeto shift, the electronic controller then directs a hydraulic system (orelectronic system in an alternative embodiment) to open and close theclutches.

Referring to FIG. 1, a feature of embodiments is that an input shaftaxis 108 of the input shaft assembly 140 is offset from a dual clutchaxis 106 of the dual clutch assembly 120. FIG. 1, further illustrates acounter shaft axis 110 of the counter shaft assembly 220, a shift railaxis 112 of the shift fork assembly 460, a shift drum axis 114 of theshift drum assembly 450 and the differential axis 116 of the outputdifferential assembly 380. In the example embodiment of FIG. 1, the dualclutch axis 106, the input shaft axis 108, the counter shaft axis 110are parallel with each other. In addition, they are transverse to thedifferential axis 116. One other feature of the dual clutch transaxle100 is that as illustrated in FIG. 1 is that the input shaft assembly140 and the counter shaft assembly 220 is position above the outputdifferential assembly 380 to achieve a compact configuration. Inaddition, in embodiments, no gear reduction is needed coming out of thedual clutch assembly 120. Although a nested dual clutch assembly 120 isillustrated in the Figures, other types of dual clutch assemblies suchas, but not limited to, serial and parallel dual clutch assemblies areused in other embodiments.

One other feature of the dual clutch transaxle 100, and otherembodiments discussed below, is that their configurations allows for aneasy change of the gear ratio. In multi speed transmission, it isdesired to have ratio splits to be consistent or close to consistentthroughout the different transaxle variants. Ratio splits are calculatedby taking the gear ratio in the second gear and dividing by the gearratios in the first gear. The gear ratio of the third gear is divided bythe gear ratio in the second gear and so on. To change the top speed ofa transaxle or to change the RPM, there need to be a place to change theratios of the gearing. The offset configuration of the dual clutchassembly 120 and the input shaft assembly 140, a simple swap out of thefirst inner clutch assembly gear 122 a and the corresponding outer inputshaft second driven gear 196 along with the second outer clutch gear 124c and the corresponding inner input shaft first driven gear 143 changesthe overall ratio of the transaxle 100 while keeping the same ratiosplits from first, second and third gear and so on. This is a mucheasier, fast and lower production cost than having to change all of theshifting gears on the input shafts 142 and 144 and the counter shaft222. Further in an embodiment, the gearing of the dual clutch transaxle100 may also be changed by changing the gearing in an idler set of theidler assembly 270 further downstream from the counter shaft assembly140. Hence, if a different gear ratio is needed for a differentapplication, this can be done by simply swapping out one more gears asdescribed above. Accordingly, the same vehicle platform with the dualclutch transaxle 100 could be used for engines running at different RPMssuch is typically the case with gasoline and diesel engines to achievedesired vehicle characteristics by swapping out the gears.

FIG. 9 illustrates a block diagram of a vehicle 500 of one embodimentimplementing the dual clutch transaxle 100 described above. The vehicle500 includes an engine 502 that provides torque to the dual clutchtransaxle 100. As described above, the torque is provided to the dualclutch 121 typically via crankshaft connection to the engine. Torque isprovide to rear wheels 508 c and 508 d via the output differentialassembly 380 of the dual clutch transaxle 100. The torque is provided toa front differential 506 through a front drive shaft 504 operationallycoupled to the front output assembly 282 of the dual clutch transaxle100. Torque is provided to the front wheels 508 a and 508 b via thefront differential 506. Further illustrated in FIG. 9 is a transmissioncontrol module 505 and a clutch actuation system 507. The clutchactuation system 507 may be an electronic or hydraulic or combinationelectric/hydraulic system that opens and closes the clutches 121 a and121 b of the dual clutch assembly 120. The transmission control unit 505controls operation of the clutch actuation system 507 and the shift drumassembly 450 in an embodiment. The transmission control unit 505, in oneembodiment, includes one or more processing units that implementinstructions, such as an algorithm, stored in a memory to cause theshift drum to rotate and the clutches to open and close during a shiftoperation of the dual clutch transaxle 100.

Another embodiment of a dual clutch transaxle 600 is illustrated inFIGS. 10 through 12. This embodiment also includes a dual clutchassembly 620, and input shaft assembly 640, a counter shaft assembly680, a shift fork assembly 700, a shift drum assembly 720, an outputdifferential assembly 740, a front output assembly 760 and a lay shaftassembly 780. Similar to the dual clutch transaxle 100 described above,the dual clutch transaxle 600 includes a dual clutch axis 602, an inputshaft axis 604 and a counter shaft axis 606 that that are all transverseto a differential axis 608. Moreover the dual clutch axis 602 is spacedfrom the input shaft axis 604 and the counter shaft axis 606. Inaddition, the output differential assembly 740 is also positioned underthe counter shaft assembly 680 and the input shaft assembly 640. In theembodiment of FIG. 10, however, the shift fork assembly 700 and theshift drum assembly 720 are positioned on the other side of the countershaft assembly 680 away from the input shaft assembly 640.

The dual clutch assembly 620 includes a first clutch drive gear 622 anda second clutch drive gear 624. The first clutch drive gear 622 engagesa first driven input gear 642 of the input shaft assembly 640 and thesecond clutch drive gear 624 engages a second driven input gear 644 ofthe input shaft assembly 640 to convey torque from an engine to theinput shaft assembly 640. Similar to the dual clutch transaxle 100discussed above, the dual clutch assembly 620 includes an inner shaftand an outer shaft to selectively provide torque to the first clutchdrive gear 622 and the second clutch drive gear 624.

Interaction between the input shaft assembly 640 and the counter shaftassembly 680 is shown in FIG. 12. The input shaft assembly 640 includesa first inner input shaft 646 upon which a second outer input shaft 648is mounted. The first inner input shaft 646 is driven by the seconddriven input gear 644. Mounted on the first inner input shaft 646 is afourth drive gear 650, a second drive gear 652 and a reverse drivesprocket 654. Mounted on the second outer input shaft 648 is a fifthdrive gear 656, a third drive gear 658 and a first drive gear 660. Thecounter shaft assembly 680 includes a fourth driven gear 684 that isengaged with the fourth drive gear 650 of the input shaft assembly 640and a second driven gear 688 that is engaged with the second drive gear652 of the input shaft assembly 640. A first shift dog 686 is mounted onthe counter shaft 682 to selectively lock rotation the counter shaft 682with rotation of either the fourth driven gear 684 or the second drivengear 688. The counter shaft assembly 680 also includes a reverse drivensprocket 690 that is coupled to the reverse drive sprocket 654 of theinput shaft assembly 640 via chain 691. A fifth driven gear 692 of thecounter shaft assembly 680 is engaged with the fifth drive gear 656 ofthe input shaft assembly 640. A third driven gear 694 is engaged withthe third drive gear 658 of the input shaft assembly 640. A first drivengear 696 is engaged with the first drive gear 660 of the input shaftassembly 640. A second shift dog 695 mounted on the counter shaft 682selectively locks rotation of the counter shaft 682 with rotation ofeither the third driven gear 694 or the first driven gear 696. A fourthshift dog 689 mounted on the counter shaft 682 selectively locksrotation of the counter shaft 682 with rotation of either the fifthdriven gear 692 or the reverse driven sprocket 690. This embodiment ofthe counter shaft assembly 680 further includes a low range drive gear697, a high range drive gear 699 and a third shift dog 698 thatselectively locks rotation of either the low range drive gear 697 or thehigh range drive gear 699 with the rotation of the counter shaft 682.Hence, in this embodiment, the dual clutch transaxle provides 10different forward gears (1 through 5 low and 1 through 5 high) and 2reverse gears (1 low and 1 high).

Referring to FIGS. 11A and 11B, the high range drive gear 699 of thecounter shaft assembly 680 is engaged with a high range driven gear 784of the lay shaft assembly 780 and the low range drive gear 697 of thecounter shaft assembly 680 is engaged with a low range driven gear 786of the lay shaft assembly 780. The lay shaft assembly 780 furtherinclude a lay shaft 782 and a lay shaft drive gear 788. The lay shaftdrive gear 788 mates with a drop gear 762 of the front output assembly760. The drop gear 762 is fixed to a second stage drive gear 764. Boththe drop gear 762 and the second stage drive gear 764 are axially andradially but not rotationally constrained to a front output shaft 763 ofthe front output assembly 760. The second stage drive gear mates with asecond stage driven gear 774 which is constrained to a bevel pinionshaft 772. Bevel pinion shaft 772 is further in operationally connectedto the ring gear of the output differential assembly 740. Drive sprocket776 is also operationally connected to the bevel pinion shaft 772. Achain 768 transmits power from the drive shaft sprocket 776 to thedriven sprocket 766 which is operationally connected to front outputshaft 763. The connection between the bevel pinion shaft 772 may be astandard bevel set with the pinion on the same axis as a ring gear ofthe output differential assembly 740 or the pinion axis may be above orbelow the ring gear axis of the differential of the output differentialassembly 740. This layout solves packaging issues by offsetting theinput shafts 646 and 648 away from a crankshaft of the motor and above aring gear and differential. The drop gears to the front driveshaft allowfor the packaging gear sets without any extra shafts while stillallowing access to a pinion on the forward side of the ring gear. Thepinion mates with the ring gear either as a bevel set or hypoid set tochange the power flow from longitudinal (front to back) to transversal(left or right). With the ring gear attached to the differential of theoutput differential assembly 740, drive shafts plug into thedifferential to deliver power to the wheels. This design may also workwith the spool rear housing where there would not be a differential inthe system. In an example embodiment, the axis of the input shaft,counter shaft and the lay shaft run above the axis of the rear gear.Moreover, in an embodiment, a silent chain is run between the lay shaft782 and front output assembly. A mesh gear could also be used dependingon the direction of rotation desired. Activation of the third shift dog698 may be done with the shift drum assembly 720 or may be done in aseparate manner such as with a cable controlled by an operator or by aseparate electric motor used to move an associated shift fork to shiftthe third shift dog 698. In another embodiment, a solenoid that slidesthe associated shift fork is used to shift it.

FIGS. 13 through 15 illustrate yet another embodiment of a dual clutchtransaxle 800. Dual clutch transaxle 800 includes a dual clutch assembly820, and input shaft assembly 840, a counter shaft assembly 880, a shiftdrum assembly 900, a shift fork assembly 920, and output differentialassembly 940, a front output assembly 960, a rear output assembly 970and a pawl park assembly 980. Similar to the dual clutch transaxles 100and 600 described above, the dual clutch transaxle 800 includes a dualclutch axis 802, an input shaft axis 804 and a counter shaft axis 806that that are all transverse to a differential axis 808. Moreover thedual clutch axis 802 is a spaced distance from the input shaft axis 804and the counter shaft axis 806. In addition, the output differentialassembly 940 is also positioned under the counter shaft assembly 880 andthe input shaft assembly 840. In this example embodiment of dual clutchtransaxle 800, the rear output assembly 970 has a rear output drivengear 972 that is engaged with a rear output drive gear 884 of thecounter shaft assembly 880. The rear output driven gear 972 is used todrive the output differential assembly 940. In an embodiment, the rearoutput assembly 970 includes a pinion that mates with a ring gear of theoutput differential assembly 940 to transfer torque to the outputdifferential assembly 940.

The dual clutch assembly 820 of the dual clutch transaxle 800 includesnested output shafts. Coupled to a first output shaft 822 of the dualclutch assembly 820 is a first torque drive gear 826. Coupled to asecond output shaft 824 of the dual clutch assembly 820 is a secondtorque drive gear 828. The first torque drive gear 826 is engaged with afirst torque driven gear 864 of the input shaft assembly 840. The secondtorque drive gear 828 is engaged with a second torque driven gear 856 ofthe input shaft assembly 840. The first torque driven gear 864 iscoupled to a second outer input shaft 844 of the input shaft assembly840. The second torque driven gear 856 is coupled to a first inner inputshaft 842 of the input shaft assembly 840. Similar to the transaxleembodiments discussed above, the gearing ratio of the dual clutchtransaxle 800 can be adjusted by simply swapping out the gearing setincluding the first torque drive gear 826 and the first torque drivengear 864 and the second gearing set including the second torque drivegear 828 and second torque driven gear 856 of the dual clutch assembly820 and the input shaft assembly 840 respectively.

FIG. 15 illustrates how the input shaft assembly 840 interacts with thecounter shaft assembly 880. A sixth drive gear 846 of the input shaftassembly 840 is engaged with a sixth driven gear 886 mounted on acounter shaft 882 of the counter shaft assembly 880. A fourth drive gear850 of the input shaft assembly 840 is engaged with a fourth driven gear888 of the counter shaft assembly 880. A first shift dog 848 mounted onthe first inner input shaft 842 of the input shaft assembly 840. Thefirst shift dog 848 is positioned to selectively lock either the sixthdrive gear 846 or the fourth drive gear 850 to the rotation of firstinner input shaft 842 of input shaft assembly 840. The input shaftassembly 840 further includes a second drive gear 852 that is engagedwith a second driven gear 890 of the counter shaft assembly 880. Areverse drive sprocket 854 is mounted on the first inner input shaft 842of the input shaft assembly 840. The reverse drive sprocket 854 is matedwith a reverse driven sprocket 893 of the counter shaft assembly 880 viachain 855. Mounted on the second outer input shaft 844 of the inputshaft assembly 840 is a fifth drive gear 858. The fifth drive gear 858is engaged with a fifth driven gear 894 of the counter shaft assembly880. A third drive gear 862 of the input shaft assembly 880 is engagedwith a third driven gear 895 of the counter shaft assembly 880. A secondshift dog 860 is mounted on the second outer input shaft 844 of theinput shaft assembly 840 to selectively lock either the fifth drive gear858 or the third drive gear 862 to the rotation of the second outerinput shaft 844 of the input shaft assembly 840. Further mounted on thesecond outer input shaft 840 is a first drive gear 866 that is engagedwith the first driven gear 896 of the counter shaft assembly 880. Thecounter shaft assembly 880 further includes a third shift dog 892 thatis positioned on the counter shaft 882 to selectively lock rotation ofthe counter shaft 882 with the rotation of either the second driven gear890 or the reverse driven sprocket 893. The counter shaft assembly 880also includes fourth shift dog 897 that is positioned on the countershaft 882 to selectively lock rotation of counter shaft 882 withrotation of the first driven gear 896.

As best illustrated in FIG. 14, this embodiment includes a park pawlassembly 980 to lock the dual clutch transaxle 800 in park. The parkpawl assembly 980 includes a pivotally connected pawl 982 that has afirst end that is engaged with the shift drum assembly 900. The shiftdrum 902 of the shift drum assembly 900 has a cam profile cut onto itsuch that as the shift drum rotates, the park pawl 982 rotates about pin986. As the park pawl 982 rotates about pin 986, a second end of thepark pawl 982 engages a notch 897 a formed in the fourth shift dog 897.The pin 986 is locked into a gear case (not shown) so when the park pawl982 locks into the fourth shift dog 897, the counter shaft 882 is lockedto the gear case and dual clutch transaxle 800 is in park. The secondend of the park pawl 982 is biased away from the fourth shift dog 897 bybias member 984. The cam profile of the shift drum 902 counters thebiasing force of the bias member 984 when placing the dual clutchtransaxle 800 into park. A park assembly may be placed anywheredownstream of the counter shaft 882 in an embodiment, as long as thepark assembly is operationally coupled to selectively lock the countershaft assembly 880.

EXAMPLE EMBODIMENTS

Example 1 includes a dual clutch transaxle that includes a dual clutchassembly, an input shaft assembly, a counter shaft assembly, a shiftassembly and at least one output assembly. The dual clutch assemblyincludes a first inner clutch shaft and a second outer clutch shaft. Thedual clutch assembly has a dual clutch axis. The dual clutch assembly isfurther configured to be coupled to receive torque from a motor. Theinput shaft assembly includes a nested first inner input shaft and asecond outer input shaft. The input shaft assembly has a plurality ofdrive gears. The input shaft assembly further has an input shaft axis.The input shaft axis is offset from the dual clutch axis of the dualclutch assembly. The first inner clutch shaft of the dual clutchassembly is operationally coupled to one of the first inner input shaftand the second outer input shaft of the input shaft assembly and thesecond outer clutch shaft of the dual clutch assembly operationallycoupled to the other of the first inner input shaft and the second outerinput shaft of the input shaft assembly. The counter shaft assembly hasa plurality of driven gears. The plurality of drive gears of the inputshaft assembly are operationally coupled to the plurality of drivengears of the counter shaft assembly. The shift assembly is operationallycoupled to at least one of the input shaft assembly and the countershaft assembly to select gearing of the dual clutch transaxle. The atleast one output assembly is operationally coupled to the counter shaftassembly. The output assembly is configured to provide an output of thedual clutch transaxle.

Example 2 includes the aspects of Example 1, wherein the first innerclutch shaft of the dual clutch assembly operationally coupled to one ofthe first inner input shaft and the second outer input shaft of theinput shaft assembly and the second outer clutch shaft of the dualclutch assembly operationally coupled to the other of the first innerinput shaft and the second outer input shaft of the input shaft assemblyfurther includes; the first inner clutch shaft operationally connectedto the second outer input shaft and the second outer clutch shaftoperationally coupled to the first inner input shaft.

Example 3 includes any of the aspects of Examples 1-2, wherein the atleast one output assembly comprises; an output differential assembly. Atleast a portion of the output differential assembly is positioned underat least one of the input shaft assembly and the counter shaft assembly.

Example 4 includes any of the aspects of Example 3, wherein outputdifferential assembly has a differential axis that is transverse to thedual clutch axis.

Example 5 includes any of the aspects of Examples 3-4, wherein the atleast one output assembly further comprises; a second output assemblyoperationally coupled to the countershaft assembly to provide a secondoutput for the dual clutch transaxle.

Example 6 includes any of the aspects of Example 5, wherein the secondoutput assembly is a front output assembly having a front output axisthat is parallel with the dual clutch axis.

Example 7 includes any of the aspects of Examples 1-6, wherein the inputshaft assembly having a plurality of drive gears further comprises; thefirst inner input shaft having at least one drive gear and a secondouter input shaft having at least one other drive gear.

Example 8 includes any of the aspects of Examples 1-7, wherein the shiftassembly is an electrically operated shift drum assembly.

Example 9 includes any of the aspects of Examples 1-8, further includinga park assembly that is operationally coupled to the counter shaftassembly to selectively lock rotation of a counter shaft during a parkconfiguration of the dual clutch transaxle.

Example 10 includes any of the aspects of Examples 1-8, wherein the dualclutch assembly includes a nested dual clutch.

Example 11 is another dual clutch transaxle. The dual clutch transaxleincludes a dual clutch assembly, an input shaft assembly, a countershaft assembly, a shift drum assembly, first output assembly and asecond output assembly. The dual clutch assembly includes a first clutchshaft and a second clutch shaft. The dual clutch assembly having a dualclutch axis. The dual clutch assembly is configured to receive torquefrom a motor. The input shaft assembly includes a nested first innerinput shaft and a second outer input shaft. The first inner input shafthas at least one drive gear and the second outer input shaft has atleast one other drive gear. The input shaft assembly further has aninput shaft axis. The first clutch shaft of the dual clutch assembly isoperationally coupled to one of the first inner input shaft and thesecond input shaft of the input shaft assembly and the second outerclutch shaft of the dual clutch assembly operationally coupled to one ofthe other of the first inner input shaft and the second outer inputshaft of the input shaft assembly. The counter shaft assembly has atleast a driven gear engaged with the at least one drive gear and atleast one other driven gear engaged with the at least one other drivegear of the input shaft assembly. The shift assembly is operationallycoupled to at least one of the input shaft assembly and the countershaft assembly to select gearing of the dual clutch transaxle. The firstoutput assembly is operationally coupled to the counter shaft assembly.The first output assembly is configured to provide a first output of thedual clutch transaxle. The first output assembly having an output axisthat is transverse and below the input shaft axis. The second outputassembly is operationally coupled to the counter shaft assembly.

Example 12 includes any of the aspects of Example 11, further includingan electric motor to rotate a shift drum of the shift drum assembly.

Example 13 includes any of the aspects of Examples 11-12, furtherincluding a park assembly operationally coupled to the counter shaftassembly to selectively lock rotation of a counter shaft during a parkconfiguration of the dual clutch transaxle.

Example 14 includes any of the aspects of Examples 11-12, wherein thefirst clutch shaft of the dual clutch assembly operationally coupled toone of the first inner input shaft and the second outer input shaft ofthe input shaft assembly and the second clutch shaft of the dual clutchassembly operationally coupled to one of the other of the first innerinput shaft and the second outer input shaft of the input shaft assemblyfurther comprises; a first gear set operationally coupling the firstclutch shaft of the dual clutch assembly operationally to one of thefirst inner input shaft and the second outer input shaft of the inputshaft assembly and a second gear set coupling the second clutch shaft ofthe dual clutch assembly operationally to one of the other of the firstinner input shaft and the second outer input shaft of the input shaftassembly. The first gear set and the second gear set configured to bereplaceable to change the overall gear ratios in the transaxle.

Example 15 includes any of the aspects of Examples 11-14, furtherincluding a low range drive gear coupled to a counter shaft of thecounter shaft assembly; a high range gear coupled to the countershaft ofthe countershaft assembly; and a lay shaft assembly engaged with the lowrange drive gear and the high range drive gear. The lay shaft assemblyis further operationally coupled to the output differential assembly andthe second output assembly.

Example 16 includes any of the aspects of Examples 11-15, wherein thedual clutch assembly includes a nested dual clutch.

Example 17 include any of the aspects of Examples 11-16, wherein thefirst output assembly further comprises an output differential assembly.

Example 18 includes a vehicle. The vehicle includes a motor, a dualclutch transaxle, a set of rear wheels, a set of front wheels and afront differential. The motor provides torque. The dual clutch transaxleincludes a dual clutch assembly, an input shaft assembly, a countershaft assembly, a first output assembly and a second output assembly.The dual clutch assembly is coupled to receive the torque from themotor. The dual clutch assembly includes a first inner clutch shaft anda second outer clutch shaft. The dual clutch assembly has a dual clutchaxis. The input shaft assembly includes a nested first inner input shaftand a second outer input shaft. The input shaft assembly has a pluralityof drive gears. The input shaft assembly further has an input shaftaxis. The input shaft axis is offset from the dual clutch axis of thedual clutch assembly. The first inner clutch shaft of the dual clutchassembly is operationally coupled to one of the first inner input shaftand the second outer input shaft of the input shaft assembly and thesecond outer clutch shaft of the dual clutch assembly operationallycoupled to the other of the first inner input shaft and the second outerinput shaft of the input shaft assembly. The counter shaft assembly hasat least a driven gear engaged with the at least one drive gear and atleast one other driven gear engaged with the at least one other drivegear of the input shaft assembly. The shift drum assembly isoperationally coupled to at least one of the input shaft assembly andthe counter shaft assembly to select gearing of the dual clutchtransaxle. The first output assembly is operationally coupled to thecounter shaft assembly. The first output assembly is configured toprovide a first output of the dual clutch transaxle. The first outputassembly has a first output axis that is transverse to the dual clutchaxis. The second output assembly is operationally coupled to the countershaft assembly. The set of rear wheels are operationally coupled to theoutput differential. The front differential is operationally coupled tothe second output and the set of front wheels is operationally coupledto the front differential.

Example 19 includes any of the aspects of Example 18, wherein the firstinner clutch shaft of the dual clutch assembly is operationally coupledto one of the first inner input shaft and the second outer input shaftof the input shaft assembly and the second outer clutch shaft of thedual clutch assembly operationally coupled to the other of the firstinner input shaft and the second outer input shaft of the input shaftassembly of the dual clutch transaxle further comprises; the first innerclutch shaft operationally connected to the second outer input shaft andthe second outer clutch shaft operationally coupled to the first innerinput shaft.

Example 20 includes any of the aspects of Examples 18-19, wherein atleast a portion of the output differential assembly of the dual clutchtransaxle is positioned under at least one of the input shaft assemblyand the counter shaft assembly.

Example 21 includes any of the aspects of Examples 18-20, wherein theinput shaft assembly of the dual clutch transaxle having a plurality ofdrive gears further comprises; the first inner input shaft having atleast one drive gear and a second outer input shaft having at least oneother drive gear.

Example 22 includes any of the aspects of Examples 18-21, wherein thedual clutch transaxle further includes an electric motor to rotate ashift drum of the shift drum assembly.

Example 23 includes any of the aspects of Examples 18-22, wherein thedual clutch transaxle further includes a park assembly operationallycoupled to the counter shaft assembly to selectively lock rotation of acounter shaft during a park configuration of the dual clutch transaxle.

Example 24 includes any of the aspects of Examples 18-23, wherein thefirst output assembly further comprises; an output differentialassembly.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement, which is calculated to achieve the same purpose,may be substituted for the specific embodiment shown. This applicationis intended to cover any adaptations or variations of the presentinvention. Therefore, it is manifestly intended that this invention belimited only by the claims and the equivalents thereof.

PARTS LIST   100-dual clutch transaxle 102-electric shift motor104-power port 106-dual clutch axis 108-input shaft axis 110-countershaft axis 112-shift rail axis 114-shift drum axis 116-differential axis120-dual clutch assembly 121-dual clutch 121a-first clutch 121b-secondclutch 122-first inner clutch shaft 122a-first inner clutch gear122b-Inner end clutch splines 123-cover plate 124-second outer clutchshaft 124a-central passage 124b-outer end clutch splines 124c-secondouter clutch gear 126-bearing 128-bearing 130-bearing 132-bearing134-bearing 136-seal 138-torque clutch input shaft 140-input shaftassembly 142-first inner input shaft 142a-splines 142b-splines 143-innerinput shaft first driven gear 144-second outer input shaft 144a-a seconddrive gear 144b-reverse drive sprocket 146-bearing 148-retaining ring150-first drive gear 152-washer 154-washer 156-bearing 158-retainingring 160-first shift dog 162-retaining clip 164-washer 166-bearing168-third drive gear 170-bearing 172-washer 174-bearing 176-bearing178-fourth drive gear 180-washer 182-retaining ring 184-third shift dog186-retaining ring 188-retaining ring 190-washer 192-bearing 194-sixthdrive gear 196-outer input shaft second driven gear 198-bearing202-bearing 204-bearing 206-fifth drive gear 208-washer 210-retainingring 212-fourth shift dog 214-bearing 220-counter shaft assembly222-counter shaft 222a-splines 222b-splines 222c-splines 222d-splines223-fourth driven gear 224-sixth driven gear 225-fifth driven gear226-bearing 228-retaining ring 230-first driven gear 232-retaining ring234-third driven gear 236-second driven gear 238-retaining ring240-second shift dog 242-bearing 244-retaining ring 246-washer248-bearing 250-sprocket 252-chain 254-retaining ring 256-counter shaftoutput drive gear 258-Park shift dog 260-retaining ring 262-bearing270-idler assembly 272-idler shaft 272a-idler gear 272b-splines274-bearing 276-second stage gear 278-retaining ring 280-bearing282-front output assembly 283-front output axis 284-front output shaft284a-front output gear 286-bearing 288-bearing 290-seal 292-thirdassembly 294-cluster shaft 296-bearing 298-bearing 302-third clustergear 304-second assembly 306-cluster shaft 308-bearing 310-secondcluster gear 312-bearing 314-first assembly 316-motor shaft 318-bearing320-bearing 322-third cluster gear 324-first pinion gear 326-bearing328-bearing 330-park assembly 332-park rail shaft 334-park pawl336-first shift park assembly 338-nut 340-bell crank 342-O-ring344-first sector gear 346-first shift shaft 348-the second sector gear350a-first portion park cam 354-second portion park cam 352-torsionspring 356-retaining ring 360-second shift park assembly 362-secondshift shaft 364-detent star 366-third sector gear 368-fourth sector gear370-O-ring 372-thrust washer 374-snap ring 380-output differentialassembly 382-bearing 384-engagement dog 386-differential carrier390-differential pin 402-washer 401-dowel pin 404-first output gear406a-first bevel pinion 406b-second bevel pinion 408-second output gear410-washer 412-ring gear 414-bearing 416-gear assembly 418-bevel pinion418a-bevel pinion gear 420-bearing 422-bearing cover 424-third stagegear 426-pinion bevel nut 428-spacer 430-forward gear 432-bearing450-shift drum assembly 452-shift drum 452a-first cam track 452b-secondcam track 452c-third cam track 452d-fourth cam track 454-bearing456-bearing 458-shift drum gear 460-shift fork assembly 462-shift rail464-first shift fork 464a-first follower tab 466-second shift fork466b-second follower tab 468-third shift fork 468c-third follower tab470-fourth shift fork 470d-fourth follower tab 500-vehicle 502-engine504-front drive shaft 506-front differential 508a-first front wheel508b-second front wheel 508c-third front wheel 508d-fourth front wheel600-Dual clutch transaxle 602-dual clutch axis 604-input shaft axis606-counter shaft axis 608-differential axis 620-dual clutch assembly622-first clutch drive gear 624-second clutch drive gear 640-input shaftassembly 642-first driven input gear 644-second driven input gear646-first inner input shaft 648-second outer input shaft 650-fourthdrive gear 652-second drive gear 654-reverse drive sprocket 656-fifthdrive gear 658-third drive gear 660-first drive gear 680-counter shaftassembly 682-counter shaft 684-fourth driven gear 686-first shift dog688-second driven gear 689-fourth shift dog 690-reverse driven sprocket691-chain 692-fifth driven gear 694-third driven gear 695-second shiftdog 696-first driven gear 697-low range gear 698-third shift dog699-high range gear 700-shift fork assembly 720-shift drum assembly740-output differential assembly 760-front output assembly 762-drop gear763-front output shaft 764-second stage drive gear 766-driven sprocket768-chain 772-bevel pinion shaft 774-second stage driven gear 776-drivesprocket 780-lay shaft assembly 782-lay shaft 784-high range driven gear786-low range driven gear 788-lay shaft drive gear 800-dual clutchtransaxle 802-dual clutch axis 804-input shaft axis 806-counter shaftaccess 808-differential axis 820-dual clutch assembly 822-first outputshaft 824-second output shaft 826-first torque drive gear 828-secondtorque drive gear 840-input shaft assembly 842-first inner input shaft844-second outer input shaft 846-sixth drive gear 848-first shift dog850-fourth drive gear 852-second drive gear 854-reverse drive sprocket855-chain 856-second torque driven gear 858-fifth drive gear 860-secondshift dog 862-third drive gear 864-first torque driven gear 866-firstdrive gear 880-counter shaft assembly 882-counter shaft 884-rear outputdrive gear 886-sixth driven gear 888-fourth driven gear 890-seconddriven gear 892-third shift dog 893-reverse driven sprocket 894-fifthdriven gear 895-third driven gear 896-first driven gear 897-fourth shiftdog 897a-notches in fourth shift dog 898-front output drive gear900-shift drum assembly 902-shift drum 920-shift fork assembly940-output differential assembly 960-front output assembly 970-rearoutput assembly 972-rear output driven gear 980-park pawl assembly982-park pawl 984-biasing member

1. A dual clutch transaxle comprising: a dual clutch assembly includinga first inner clutch shaft and a second outer clutch shaft, the dualclutch assembly having a dual clutch axis, the dual clutch assemblyconfigured to be couple to receive torque from a motor; an input shaftassembly including a nested first inner input shaft and a second outerinput shaft, the input shaft assembly having a plurality of drive gears,the input shaft assembly further having an input shaft axis, the inputshaft axis being offset from the dual clutch axis of the dual clutchassembly, the first inner clutch shaft of the dual clutch assemblyoperationally coupled to one of the first inner input shaft and thesecond outer input shaft of the input shaft assembly and the secondouter clutch shaft of the dual clutch assembly operationally coupled tothe other of the first inner input shaft and the second outer inputshaft of the input shaft assembly; a counter shaft assembly having aplurality of driven gears, the plurality of drive gears of the inputshaft assembly operationally coupled to the plurality of driven gears ofthe counter shaft assembly; a shift assembly operationally coupled to atleast one of the input shaft assembly and the counter shaft assembly toselect gearing of the dual clutch transaxle; and at least one outputassembly operationally coupled to the counter shaft assembly, the outputassembly configured to provide an output of the dual clutch transaxle.2. The dual clutch transaxle of the claim 1, wherein the first innerclutch shaft of the dual clutch assembly operationally coupled to one ofthe first inner input shaft and the second outer input shaft of theinput shaft assembly and the second outer clutch shaft of the dualclutch assembly operationally coupled to the other of the first innerinput shaft and the second outer input shaft of the input shaft assemblyfurther comprises: the first inner clutch shaft operationally connectedto the second outer input shaft and the second outer clutch shaftoperationally coupled to the first inner input shaft.
 3. The dual clutchtransaxle of the claim 1, wherein the at least one output assemblyfurther comprises: an output differential assembly, at least a portionof the output differential assembly being positioned under at least oneof the input shaft assembly and the counter shaft assembly.
 4. The dualclutch transaxle of claim 3, wherein the output differential assemblyhas a differential axis that is transverse to the dual clutch axis. 5.The dual clutch transaxle of claim 3, wherein the at least one outputassembly further comprises: a second output assembly operationallycoupled to the countershaft assembly to provide a second output for thedual clutch transaxle.
 6. The dual clutch transaxle of claim 5, whereinthe second output assembly is a front output assembly having a frontoutput axis that is parallel with the dual clutch axis.
 7. The dualclutch transaxle of claim 1, wherein the input shaft assembly having aplurality of drive gears further comprises: the first inner input shafthaving at least one drive gear and a second outer input shaft having atleast one other drive gear.
 8. The dual clutch transaxle of claim 1,wherein the shift assembly is an electrically operated shift drumassembly.
 9. The dual clutch transaxle of claim 1, further comprising: apark assembly operationally coupled to the counter shaft assembly toselectively lock rotation of a counter shaft during a park configurationof the dual clutch transaxle.
 10. The dual clutch transaxle of claim 1,wherein the dual clutch assembly includes a nested dual clutch.
 11. Adual clutch transaxle comprising: a dual clutch assembly including afirst clutch shaft and a second clutch shaft, the dual assembly having adual clutch axis, the dual clutch assembly configured receive torquefrom a motor; an input shaft assembly including a nested first innerinput shaft and a second outer input shaft, the first inner input shafthaving at least one drive gear and the second outer input shaft havingat least one other drive gear, the input shaft assembly further havingan input shaft axis, the first clutch shaft of the dual clutch assemblyoperationally coupled to one of the first inner input shaft and thesecond input shaft of the input shaft assembly and the second outerclutch shaft of the dual clutch assembly operationally coupled to one ofthe other of the first inner input shaft and the second outer inputshaft of the input shaft assembly; a counter shaft assembly having atleast a driven gear engaged with the at least one drive gear and atleast one other driven gear engaged with the at least one other drivegear of the input shaft assembly; a shift assembly operationally coupledto at least one of the input shaft assembly and the counter shaftassembly to select gearing of the dual clutch transaxle; a first outputassembly operationally coupled to the counter shaft assembly, the firstoutput assembly configured to provide a first output of the dual clutchtransaxle, the first output assembly having an output axis that istransverse to and below the input shaft axis; and a second outputassembly operationally coupled to the counter shaft assembly.
 12. Thedual clutch transaxle of claim 11, further comprising: an electric motorto rotate a shift drum of the shift drum assembly.
 13. The dual clutchtransaxle of claim 11, further comprising: a park assembly operationallycoupled to the counter shaft assembly to selectively lock rotation of acounter shaft during a park configuration of the dual clutch transaxle.14. The dual clutch transaxle of claim 11, wherein the first clutchshaft of the dual clutch assembly operationally coupled to one of thefirst inner input shaft and the second outer input shaft of the inputshaft assembly and the second clutch shaft of the dual clutch assemblyoperationally coupled to one of the other of the first inner input shaftand the second outer input shaft of the input shaft assembly furthercomprises: a first gear set operationally coupling the first clutchshaft of the dual clutch assembly operationally to one of the firstinner input shaft and the second outer input shaft of the input shaftassembly and a second gear set coupling the second clutch shaft of thedual clutch assembly operationally to one of the other of the firstinner input shaft and the second outer input shaft of the input shaftassembly, the first gear set and the second gear set configured to bereplaceable to change the overall gear ratios in the dual clutchtransaxle.
 15. The dual clutch transaxle of claim 11, furthercomprising: a low range drive gear coupled to a counter shaft of thecounter shaft assembly; a high range gear coupled to the countershaft ofthe countershaft assembly; and a lay shaft assembly engaged with the lowrange drive gear and the high range drive gear, the lay shaft assemblyfurther operationally coupled to the output differential assembly andthe second output assembly.
 16. The dual clutch transaxle of claim 11,wherein the dual clutch assembly includes a nested dual clutch.
 17. Thedual clutch transaxle of the claim 11, wherein the first output assemblyfurther comprises: an output differential assembly.
 18. A vehiclecomprising: a motor to provide torque; a dual clutch transaxleincluding, a dual clutch assembly coupled to receive the torque from themotor, the dual clutch assembly including a first inner clutch shaft anda second outer clutch shaft, the dual clutch assembly having a dualclutch axis, an input shaft assembly including a nested first innerinput shaft and a second outer input shaft, the input shaft assemblyhaving a plurality of drive gears, the input shaft assembly furtherhaving an input shaft axis, the input shaft axis being offset from thedual clutch axis of the dual clutch assembly, the first inner clutchshaft of the dual clutch assembly operationally coupled to one of thefirst inner input shaft and the second outer input shaft of the inputshaft assembly and the second outer clutch shaft of the dual clutchassembly operationally coupled to the other of the first inner inputshaft and the second outer input shaft of the input shaft assembly, acounter shaft assembly having at least a driven gear engaged with the atleast one drive gear and at least one other driven gear engaged with theat least one other drive gear of the input shaft assembly, a shift drumassembly operationally coupled to at least one of the input shaftassembly and the counter shaft assembly to select gearing of the dualclutch transaxle, an first output assembly operationally coupled to thecounter shaft assembly, the first output assembly configured to providea first output of the dual clutch transaxle, the first output assemblyhaving a first output axis that is transverse to the dual clutch axis,and a second output assembly operationally coupled to the counter shaftassembly, a set of rear wheels operationally coupled to the outputdifferential; a front differential operationally coupled to the secondoutput; and a set of front wheels operationally coupled to the frontdifferential.
 19. The vehicle of the claim 18, wherein the first innerclutch shaft of the dual clutch assembly operationally coupled to one ofthe first inner input shaft and the second outer input shaft of theinput shaft assembly and the second outer clutch shaft of the dualclutch assembly operationally coupled to the other of the first innerinput shaft and the second outer input shaft of the input shaft assemblyof the dual clutch transaxle further comprises: the first inner clutchshaft operationally connected to the second outer input shaft and thesecond outer clutch shaft operationally coupled to the first inner inputshaft.
 20. The vehicle of the claim 18, wherein at least a portion ofthe first output assembly of the dual clutch transaxle is positionedunder at least one of the input shaft assembly and the counter shaftassembly.
 21. The vehicle of claim 18, wherein the input shaft assemblyof the dual clutch transaxle having a plurality of drive gears furthercomprises: the first inner input shaft having at least one drive gearand a second outer input shaft having at least one other drive gear. 22.The vehicle of claim 18, wherein the dual clutch transaxle furthercomprises: an electric motor to rotate a shift drum of the shift drumassembly.
 23. The vehicle of claim 18, wherein the dual clutch transaxlefurther comprises: a park assembly operationally coupled to the countershaft assembly to selectively lock rotation of a counter shaft during apark configuration of the dual clutch transaxle.
 24. The vehicle of theclaim 18, wherein the first output assembly further comprises: an outputdifferential assembly.